Estimated Protein Intake Research Articles

Validation of a plate diagram sheet for estimation of energy and protein intake in hospitalized patients

Validation of simple methods for estimating energy and protein intakes in hospital wards are rarely reported in the literature. The aim was to validate a plate diagram sheet for estimation of energy and protein intakes of patients by comparison with weighed food records. Subjects were inpatients at the Cardio Thoracic ward, Landspitali National University Hospital, Reykjavik, Iceland (N=73). The ward personnel used a plate diagram sheet to record the proportion (0%, 25%, 50%, 100%) of meals consumed by each subjects, for three days. Weighed food records where used as a reference method. On average the plate diagram sheet overestimated energy intake by 45kcal/day (1119±353kcal/day versus 1074±360kcal/day, p=0.008). Estimation of protein intake was not significantly different between the two methods (50.2±16.4g/day versus 48.7±17.7g/day, p=0.123). By analysing only the meals where ≤50% of the served meals were consumed, according to the plate diagram recording, a slight underestimation was observed. A plate diagram sheet can be used to estimate energy and protein intakes with fair accuracy in hospitalized patients, especially at the group level. Importantly, the plate diagram sheet did not overestimate intakes in patients with a low food intake.

Effect of differences in parenteral nutrition policies on preterm macronutrient intake: a telephone survey of all UK level 3 neonatal services: Abstract G69 Table 1

Background A recent UK national audit revealed large variations in parenteral nutrition (PN) administration in a subgroup of neonatal patients1. The factors involved included timeliness, nutritional adequacy and metabolic complications. It was not clear how much of this variation was due to differences in PN policy or whether very preterm infants (the most PN dependent) were more at risk. Aim To estimate macronutrient intakes in very preterm infants resulting from local PN policy implementation in all level 3 UK neonatal services. Methods A telephone survey using a structured questionnaire was performed Aug-Nov 2011. This recorded all factors affecting early PN supply and administration utilising information from the local PN guideline (infants Results All 60 UK level 3 (or equivalent) neonatal services provided data. Neonatal PN prescription/supply was wholly individualised (10%), individualised hybridised with standardised (56%), customised standardised (17%) or wholly standardised (17%). In only 2/60 units did local guidelines aim to introduce PN immediately after birth with 18/60 delaying >24 hours (6/60 due PN supply arrangements). This impacted on estimated early protein intake in particular (table 1). Estimated protein intakes were Hyperglycaemia management protocols involved routine (68%) versus rare/never (32%) insulin treatment and routine (48%) versus rare/never (52%) reduction in glucose intake. Hypertriglyceridaemia (leading to intravenous lipid reduction) was monitored in 35 (58%) units. Conclusion There is wide variation between UK level 3 neonatal services in the estimated macronutrient intake some of which results from local organisation of PN provision. There are opposing PN policy differences on the early introduction of protein, insulin-treated hyperglycaemia and triglyceride monitoring.

Dietary intake in women consuming three supplements with identical micronutrient content

Objectiveto estimate energy, protein, iron, zinc, and folate intake from diet only and diet+supplement in women participants in a randomized controlled supplementation trial in Mexico.MethodsCommunities randomly assigned (18/suppl) to receive a fortified beverage (FB), micronutrient tablet, or micronutrient powder. Pregnant women (<25 wks), beneficiaries of Oportunidades were eligible to participate. Dietary intake was assessed by food frequency questionnaire (FFQ, previous month) 37 wks preg, 1 and 3 mo postpartum. Supplements were delivered and consumption estimated by observation (first 9 mo) then weekly (maternal report) for the rest of the trial. Comparisons among supplementation groups were using statistical analyses for cluster randomized trials.Results694 women began supplementation (FB =224, T=235, MNP=235) and 571 (82%) finished the study; there were no significant differences among groups at baseline. Total protein intake from diet+supplements was higher in the FB (p<0.05), with no difference in diet or total energy or micronutrients.ConclusionsEnergy intake is high and likely overestimated by our FFQ; but we have no reason to believe that overestimation varies by group. The additional protein from FB in this population may not be needed as dietary intakes appear adequate.The Oportunidades program financed this study and holds the rights to the data presented.

Design aspects of 24 h recall assessments may affect the estimates of protein and potassium intake in dietary surveys

To evaluate the impact of different modes of administration (face-to-face v. telephone), recall days (first v. second), days of the week (weekday v. weekend) and interview days (1 d later v. 2 d later) on bias in protein and K intakes collected with 24 h dietary recalls (24-HDR). Two non-consecutive 24-HDR (collected with standardised EPIC-Soft software) were used to estimate protein and K intakes by a face-to-face interview at the research centres and a telephone interview, and included all days of the week. Two 24 h urine collections were used to determine biomarkers of protein and K intake. The bias in intake was defined as the ratio between the 24-HDR estimate and the biomarker. Five centres in Belgium, Czech Republic, France, the Netherlands and Norway in the European Food Consumption Validation (EFCOVAL) study. About 120 adults (aged 45-65 years) per centre. The bias in protein intake in the Czech Republic and Norway was smaller for telephone than face-to-face interviews (P = 0·01). The second 24-HDR estimates of protein intake in France and K intake in Belgium had a larger bias than the first 24-HDR (P = 0·01 and 0·04, respectively). In the Czech Republic, protein intake estimated during weekends and K intake estimated during weekdays had a larger bias than during other days of the week (P = 0·01). In addition, K intake collected 2 d later in the Czech Republic was likely to be overestimated. The biases in protein and K intakes were comparable between modes of administration, recall days, days of the week and interview days in some, but not all, study centres.

δ15N and δ13C in hair from newborn infants and their mothers: a cohort study

Protein intake in fetal life or infancy may play a key role in determining early growth rate, a determinant of later health and disease. Previous work has indicated that hair isotopic composition is influenced by diet and protein intake. This study analyzes the isotopic composition of hair obtained from 239 mother/newborn pairs randomly selected within a larger cohort enrolled in a study of pre- and postnatal determinants of the child's development and health. The isotopic compositions in nitrogen (δ(15)N) and in carbon (δ(13)C) were determined by isotope ratio mass spectrometry. Mother and newborn hair δ(15)N were tightly correlated (Pearson r = 0.88). The mean δ(15)N and δ(13)C values of hair from newborn infants were significantly higher than those for the mothers: 9.7 ± 0.7 vs. 8.8 ± 0.6‰ (P < 0.0001) for δ(15)N and -20.0 ± 0.4 vs. -20.4 ± 0.4‰ (P < 0.0001) for δ(13)C. Maternal hair δ(15)N at parturition was slightly and positively correlated with estimates of protein intake (r = 0.14, P = 0.04). Hair δ(15)N of the fetus is both highly dependent on and systematically higher than that of the mother. Whether quantitative and qualitative protein intake, disease, or hormonal status alter hair δ(15)N at birth remains to be determined.

Higher Biomarker-Calibrated Protein Intake Is Not Associated with Impaired Renal Function in Postmenopausal Women ,

AbstractWith aging, renal function tends to decline, as evidenced by reduced glomerular filtration rate. High-protein intake may further stress the kidneys by causing sustained hyperfiltration. To investigate whether dietary protein is associated with impaired renal function, we used data from 2 nested case-control studies within the Women's Health Initiative Observational Study (n= 2419). We estimated protein intake using a FFQ and estimated glomerular filtration rate (eGFR) from cystatin C. To account for the original study designs, inverse probability weights were applied. Self-reported energy and protein were calibrated using biomarkers of energy and protein intake. Associations between protein intake and renal function were estimated by weighted linear and logistic regression models. Average calibrated protein intake (mean ± SD) was 1.1 ± 0.2 g/(kg body weightd).Twelve percent (n= 292) of women had impaired renal function. The odds of impaired renal function, defined as eGFR <60 mL/(min1.73m2), was not associated with calibrated protein intake. When eGFR was modeled continuously, there was no association with calibrated protein when protein was expressed in absolute (g/d) or relative to energy (protein % energy/d), but protein relative to body weight [g/(kg body weightd)] was associated with higher eGFR. There was no evidence for effect modification by age, BMI, or general health status. These data suggest higher protein intake is not associated with impaired renal function among postmenopausal women without a diagnosis of chronic kidney disease.

Changes in dietary protein intake has no effect on serum cystatin C levels independent of the glomerular filtration rate

Cystatin C is being considered as a replacement for serum creatinine in the estimation of the glomerular filtration rate (GFR); however, its plasma levels might be affected by factors other than the GFR, such as protein intake. We performed a post hoc analysis of the data in the Modification of Diet in Renal Disease study, in which we compared serum creatinine and cystatin C levels in 741 patients with available estimates of protein intake at baseline prior to their randomization to diets containing various amounts of protein, and at 2 years of follow-up in 426 of these patients in whom a cystatin C measurement was available. The 503 patients in study A (GFR 25-55 ml/min per 1.73 m(2)) had been assigned a low (0.58 g/kg per day) or a usual (1.3 g/kg per day) protein intake, and the 238 participants in study B (GFR 13-24 ml/min per 1.73 m(2)) were assigned a very low (0.28 g/kg per day) or the low protein intake. In either study group, lowering the dietary protein intake reduced the change in creatinine, but did not have a significant change in cystatin C. Thus, in patients with moderate-to-severe chronic kidney disease, serum cystatin C unlike serum creatinine was not affected by dietary protein intake independent of changes in GFR. Hence, cystatin C may allow more accurate estimates of GFR than creatinine for patients with reduced protein intake. Further study of other non-GFR determinants of cystatin C is needed before the widespread adoption.

Urea Nitrogen Concentrations in Spot Urine, Estimated Protein Intake and Blood Pressure Levels in a Japanese General Population

An inverse association between total protein intake and blood pressure has been reported in Western countries. Such evidence is limited in the Japanese population, however, whose major protein sources are plants and seafood. We conducted a population-based cross-sectional study of 986 men and 1,636 women, aged 40-74 years, in a Japanese rural community to examine the association between blood pressure levels and urea nitrogen concentrations in spot urine. The concentration of urea nitrogen in spot urine, an indicator of total protein intake that was validated by 24-h urea nitrogen excretion and 24-h dietary research, was inversely associated with systolic blood pressure levels for men: a 238 mg/dl increase in urea nitrogen concentration was associated with a 2.1 mm Hg lower mean systolic blood pressure. For women, a weaker and nonsignificant inverse association was observed. There was no association between urea nitrogen concentrations and diastolic blood pressure levels in either sex. Total protein intake estimated from spot urine was also inversely associated with systolic blood pressure levels for men: a 19.2 g/day increase in estimated protein intake was associated with a 1.5 mm Hg lower mean systolic blood pressure. A urinary biomarker for total protein intake was inversely associated with systolic blood pressure levels for men in a Japanese general population.

Sodium-sensitive variability of the antiproteinuric efficacy of RAS inhibitors in outpatients with IgA nephropathy

Inhibition of the renin-angiotensin system (RAS) decreases proteinuria in IgA nephropathy and often retards disease progression. However, its antiproteinuric efficacy varies considerably among patients or different stages in a single patient. We sought for the factor(s) underlying the variation in urinary protein excretion in RAS inhibitor-treated outpatients with IgA nephropathy. 43 patients with biopsy-proven IgA nephropathy, moderate proteinuria (0.5 - 3.5 g/day), normal to moderately-low estimated GFR (eGFR) (28.6 - 114.2 ml/min/1.73 m2) and normal blood pressure, prehypertension or mild hypertension (systolic/diastolic blood pressures < 160/100 mmHg) were placed on RAS inhibitors following diagnosis. Excretion of urinary protein (UprV) and sodium (UNaV), estimated protein intake (EPI) and the mean blood pressure (MBP) were determined on 12 consecutive visits for an average duration of 17.6 months. Analyses were performed to determine which factor(s) influenced the variation in UprV. 14 patients (32.6%) showed a significant correlation between UprV and UNaV, whereas UprV correlated significantly with EPI or MBP in 7 (16.3%) and 3 patients (7.0%), respectively. The 14 patients were characterized by lower eGFR and more extensive glomerulosclerosis and tubulointerstitial damage at baseline than the other 29 patients. The UprV-UNaV correlation was significant in 8 of 12 patients (66.7%) with eGFR < 60 ml/min/1.73 m2 and in 6 of 29 patients (19.4%) with eGFR >= 60 ml/min/1.73 m2 (p < 0.05). The UprV/UNaV regression lines were significantly steeper with more extensive glomerulosclerosis (p < 0.05) and tubulointerstitial damage (p < 0.05) at baseline. The lines also tended to be steeper with lower baseline eGFR (p = 0.062). These results showed that the antiproteinuric effect of RAS inhibitors becomes susceptible to an increase in urinary sodium excretion as renal function and functioning nephron mass decline with the progression of renal histological damage. Stringent dietary sodium restriction is required to maximize the antiproteinuric effect of RAS inhibitors in outpatients with IgA nephropathy.

Estimation of protein intake using urinary urea nitrogen in patients with liver cirrhosis

Objective. Evaluation of protein intake of patients with liver cirrhosis (LC) would facilitate optimal nutritional support. However, this has never been done based on urinary urea nitrogen (UUN). The aim of this study was to determine the usefulness of the estimated protein intake (EPI) based on UUN in patients with LC. Material and methods. Eighty-two patients with LC were enrolled in this study. The actual protein intake (API) was defined as the dietary protein intake (1.0 g/kg/day) plus supplementation of any enteral diets containing branched-chain amino acids (BCAA). We calculated EPI from UUN using the formula [(UUN (g/day) + 0.031 × body-weight (kg)) ×0.625]. We examined the correlation between EPI and API and the EPI/API ratio (EAR), and the correction based on the results. Results. A significant positive correlation was found between API and EPI (r=0.72, p<0.001). The EAR in all patients was 0.82±0.13. EPI × 1.2 was the correction needed to adjust EAR to 1. The corrected EPI was correlated with API (r=0.704, p<0.001). The corrected EAR of all 82 patients was 0.99±0.16. Conclusions. EPI calculated from UUN is a useful tool for optimal nutritional support in LC patients, and our correction greatly improves EPI accuracy.

Fiber‐bound nitrogen in gorilla diets: implications for estimating dietary protein intake of primates

Protein is essential for living organisms, but digestibility of crude protein is poorly understood and difficult to predict. Nitrogen is used to estimate protein content because nitrogen is a component of the amino acids that comprise protein, but a substantial portion of the nitrogen in plants may be bound to fiber in an indigestible form. To estimate the amount of crude protein that is unavailable in the diets of mountain gorillas (Gorilla beringei) in Bwindi Impenetrable National Park, Uganda, foods routinely eaten were analyzed to determine the amount of nitrogen bound to the acid-detergent fiber residue. The amount of fiber-bound nitrogen varied among plant parts: herbaceous leaves 14.5+/-8.9% (reported as a percentage of crude protein on a dry matter (DM) basis), tree leaves (16.1+/-6.7% DM), pith/herbaceous peel (26.2+/-8.9% DM), fruit (34.7+/-17.8% DM), bark (43.8+/-15.6% DM), and decaying wood (85.2+/-14.6% DM). When crude protein and available protein intake of adult gorillas was estimated over a year, 15.1% of the dietary crude protein was indigestible. These results indicate that the proportion of fiber-bound protein in primate diets should be considered when estimating protein intake, food selection, and food/habitat quality.

Effect of educational hospitalization on chronic kidney disease (CKD) patients

Although dietary control is recommended to chronic kidney disease (CKD) patients, improvement of compliance and education of outpatients are very difficult. The purposes of the present study are to estimate the dietary intake of sodium (Na) and protein by measuring urinary Na and urea nitrogen (UN) excretion, and to evaluate the efficacy of educational hospitalization. 70 patients (41 men and 29 women) with a mean age of 58.7+/-15.8 years participated in the present study. Most patients had chronic kidney disease (CKD, Stage 3 or 4). Patients were hospitalized to learn about their diseases and dietary restrictions for 1 week. Patients were given low salt (less than 6 g/day) and low protein (0.6-1.0 g/standard body weight kg/day) diet. 24-hour urine samples were collected at the start (Day 2) and on completion (Day 7) of hospitalization. Salt and protein intakes were estimated using patients' 24-hour urine samples. Estimated salt intake was significantly decreased on completion of the hospitalization (Day 7) (p < 0.05). Estimated protein intake was also decreased slightly, but this was not statistically significant. There were significant differences in the changes of body weight, body mass index (BMI), and systolic and diastolic blood pressure between the start (Day 2) and completion (Day 7) of hospitalization. 89% of the patients showed an improved blood pressure without changes of antihypertensive drugs. It appears that short-term hospitalization is an effective program for achieving dietary and blood pressure control in CKD patients.

Protein Requirements of Very Low Birth Weight Infants

To review existing information regarding protein (and energy) requirements of very low birth weight infants, and to determine whether revisions may be indicated in view of the commonly observed postnatal growth failure, or in view of adverse consequences of accelerated growth. Nutrient requirements of very low birth weight infants have been estimated by the factorial method and by empirical methods. These approaches yield similar estimates of nutrient requirements. The factorial method provides estimates of requirements for protein and energy, including those of extremely small infants. Empirical methods yield estimates of protein requirements but tend to exclude extremely small infants. They also provide estimates of protein intakes that lead to catch-up growth. Reports of actual nutrient intakes received by very low birth weight infants show that intakes are generally less than estimated requirements. Growth failure is adequately explained by insufficient nutrient intakes. Upward revision of requirements is not indicated until it can be shown that growth failure occurs despite intakes that match current estimates of requirements. Downward revision also is not indicated because accelerated growth, in spite of some adverse effects later in life, is associated with improved neurocognitive outcome.

Estimation of protein intake using urinary urea nitrogen in patients with early-stage liver cirrhosis

Evaluation of protein intake of patients with liver cirrhosis (LC) would facilitate optimal nutritional support. However, it has never been done on the basis of urinary urea nitrogen (UUN). The aim of this study, therefore, is to determine the usefulness of the estimated protein intake (EPI) based on UUN in patients with LC. A total of 42 patients with early-stage LC were enrolled in this study. The actual protein intake (API) was defined as the dietary protein intake (1.0 g/kg/d) plus supplementation of any enteral diets containing branched-chain amino acids (BCAA). We calculated EPI from UUN using the formula [UUN (g/d) + 0.031 x body weight (kg)] x 0.625. We examined the correlation between EPI and API, the EPI/API ratio (EAR), and the correction based on the results. A significant positive correlation was found between API and EPI (r = 0.703, p < 0.001). The EAR in all patients was 0.84 +/- 0.11. EPI times 1.2 was the correction needed to adjust EAR to 1. The corrected EPI was correlated with API (r = 0.704, p < 0.001). The corrected EAR of all 42 patients was 1.01 +/- 0.13. In conclusion, for patients with early-stage LC, an EPI calculated from UUN may be a useful tool for optimal nutritional support. The corrected EPI would be very useful for improved monitoring of early-stage LC.

Ethnic Differences in Relative Risk of Idiopathic Calcium Nephrolithiasis in North America

Data on susceptibility to kidney stone disease are sparse in individuals of nonEuropean ancestry residing in North America. We determined the relative risk of calcium nephrolithiasis among people of different ethnic backgrounds living in the same geographic region. Using a cross-sectional design 1,128 consecutive patients with idiopathic calcium nephrolithiasis 18 to 50 years old were recruited from a population based Kidney Stone Center in Toronto. Age and gender adjusted odds ratios and 95% confidence intervals were calculated by logistic regression using the 2001 Canada Census population data. Compared to Europeans the relative risk of calcium nephrolithiasis was significantly higher in individuals of Arabic (OR 3.8, 2.7-5.2), West Indian (OR 2.5, 1.8-3.4), West Asian (OR 2.4, 1.7-3.4) and Latin American (OR 1.7, 1.2-2.4) origin, and significantly lower in those of East Asian (OR 0.4, 0.3-0.5) and African (OR 0.7, 0.5-0.9) background. Several ethnic groups had kidney stone risk factors that were significantly different from those of the European group including higher urinary uric acid, urea excretion and estimated protein intake, and lower urinary citrate, potassium, magnesium and phosphate excretion. However, none was consistent with the variation in relative risk of stone disease overall. The propensity for the development of calcium nephrolithiasis differed markedly among ethnic groups in North America. While environmental factors could not be completely ruled out, this variability may reflect the influence of genetic susceptibility because there was no dominant environmental factor to account for the differences in relative risk of stone disease.

Magnetic Resonance Measurements of Renal Blood Flow and Disease Progression in Autosomal Dominant Polycystic Kidney Disease

Whether changes in renal blood flow (RBF) are associated with and possibly contribute to cystic disease progression in autosomal dominant polycystic kidney disease (ADPKD) has not been ascertained. The Consortium for Radiologic Imaging Studies of Polycystic Kidney Disease (CRISP) was created to develop imaging techniques and analyses to evaluate progression. A total of 131 participants with early ADPKD had measurements of RBF and total kidney (TKV) and cyst (TCV) volumes by magnetic resonance and of GFR by iothalamate clearance at baseline and 1, 2, and 3 yr. The effects of age, gender, body mass index, hypertension status, mean arterial pressure (MAP), TKV, TCV, RBF, renal vascular resistance (RVR), GFR, serum uric acid, HDL and LDL cholesterol, 24-h urine volume, sodium (UNaE) and albumin (UAE) excretions, and estimated protein intake were examined at baseline on TKV, TCV, and GFR slopes. TKV and TCV increased, RBF decreased, and GFR remained stable. TKV, TCV, RVR, serum uric acid, UAE, UNaE, age, body mass index, MAP, and estimated protein intake were positively and RBF and GFR negatively correlated with TKV and TCV slopes. TKV, RBF, UNaE, and UAE were independent predictors of TKV and TCV slopes (structural disease progression). TKV, TCV, RVR, and MAP were negatively and RBF positively correlated with GFR slopes. Regression to the mean confounded the analysis of GFR slopes. TKV and RBF were independent predictors of GFR decline (functional disease progression). In ADPKD, RBF reduction (1) parallels TKV increase, (2) precedes GFR decline, and (3) predicts structural and functional disease progression.

Are insulin-like growth factor and its binding proteins 1 and 3 clinically useful as markers of malnutrition, sarcopenia and inflammation in end-stage renal disease?

Malnutrition is common in end-stage renal disease (ESRD) and affects both morbidity and mortality. The growth hormone-dependent insulin-like growth factor (IGF)-I may be a good marker of malnutrition because of its short half-life. In the present study, we investigate the influence of decreasing residual renal function as well as of chronic inflammation on the IGF system to assess its usefulness in this patient group. Cross-sectional analysis of 220 ESRD patients (140 males) with a mean age of 52+/-1 years. Biochemical analyses of insulin, IGF-I, IGFBP-1, IGFBP-3, IL-6, high sensitivity (hs)-CRP and other routine markers. Malnutrition status was recorded using subjective global assessment (SGA), body mass index, estimated protein intake from nitrogen appearance (nPNA), handgrip strength (HGS) and insulin resistance (HOMA-IR). Dual energy X-ray absorptiometry was used to assess body composition. Both IGF-I and IGFBP-1 showed significant and opposite correlations with most markers of nutritional status, including SGA (rho=-0.29 and 0.27; P<0.001), nPNA (rho=0.18 and -0.22; P<0.05), S-creatinine (rho=0.19 and -0.19; P<0.01) and HGS (rho=0.21 and -0.25; P<0.01). IFG-I was strongly correlated with IGFBP-3 (rho=0.62; P<0.001) and inversely correlated with IGFBP-1 (rho=0.44; P<0.001). Both IGF-I and IGFBP-3, but not IGFBP-1, were significantly correlated with age (rho=-0.25 for IGF-I and -0.35 for IGFBP-3; P<0.001) and hsCRP (rho=-0.21 and -0.32; P<0.01). In multivariate analysis, SGA and s-albumin were independent predictors of both IGF-I and IGFBP-1. Both IGF-I and IGFBP-1 appear to correlate well with markers of protein-energy malnutrition and sarcopenia. However, IGF-I is also influenced by age, whereas IGFBP-1 is influenced by glucose metabolism. IGFBP-3 does not correlate with nutritional status in ESRD, perhaps because of a strong association with inflammation.

Association of Socio-psychological Factors with the Effects of Low Protein Diet for the Prevention of the Progression of Chronic Renal Failure

Our objectives were to investigate the therapeutic effects of low protein diet (LPD) for chronic renal failure (CRF) in compliant patients with the diet, and to clarify the relationships to the sociopsychological factors. Sixty-five patients (47 men and 18 women) with CRF who followed LPD (0.69 g/kg/day) for more than 3 months were recruited in this study. Compliance with the diet therapy was strictly assessed by the patients' dietary records, subsequent interviews regarding the status of daily dietary intake and estimated protein intakes calculated from urinary nitrogen excretion by 24-hour urine collections. The changes of glomerular filtration rate (GFR), serum creatinine (Cr), blood urea nitrogen (BUN), the reciprocal of serum creatinine (1/Cr), scores of Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), scales of Profile of Mood States (POMS), scores of self-efficacy and social support were investigated. Decline rate of GFR, elevation of Cr and BUN and reduction in 1/Cr were significantly lower in compliant patients than in noncompliant patients (p<0.05). There were no differences in SF36 scores between compliant and noncompliant patients. The POMS scales of depression/dejection were high in female noncompliant patients compared to other groups of patients (p<0.05). Self-efficacy score was higher in compliant patients than in noncompliant patients (p<0.05). Social support scores were significantly higher in male compliant patients than in others (p<0.05), and both emotional support and behavioral support showed interaction with both gender and compliance with diet therapy (p<0.05). LPD therapy is effective in suppressing the progression of CRF when it is well-adhered to. There are no correlations of this diet therapy to health-related QOL. Social support and high self-efficacy for men and high self-efficacy for women are associated with improvement of the compliance with LPD therapy, leading to good therapeutic effects.

Association between Serum Bicarbonate and Death in Hemodialysis Patients

The optimal acid-base status for survival in maintenance hemodialysis (MHD) patients remains controversial. According to recent reports, acidosis is associated with improved survival in MHD patients. It was hypothesized that this inverse association is due to a confounding effect of the malnutrition-inflammation complex syndrome (MICS). Associations between baseline (first 3 mo averaged) predialysis serum bicarbonate (HCO3(-)) and 2-yr mortality were examined in 56,385 MHD patients who were treated in virtually all DaVita dialysis clinics across the United States. The range of HCO3(-) was divided into 12 categories (< 17, > or = 27, and 10 groups in between). Three sets of Cox regression models were evaluated to estimate hazard ratios of all-cause and cardiovascular death in both incident and prevalent patients: (1) Unadjusted, (2) multivariate case mix adjusted (which also included dialysate HCO3(-) and Kt/V), and (3) adjusted for case mix and nine markers of MICS (body mass index; erythropoietin dose; protein intake; serum albumin; creatinine; phosphorus; calcium; ferritin and total iron binding capacity; and blood hemoglobin, WBC, and lymphocytes). There were significant inverse associations between serum HCO3(-) and serum phosphorus and estimated protein intake. The lowest unadjusted mortality was associated with predialysis HCO3(-) in the 17- to 23-mEq/L range, whereas values > or = 23 mEq/L were associated with progressively higher all-cause and cardiovascular death rates. This association, however, reversed after case-mix and MICS multivariate adjustment, so that HCO3(-) values >22 mEq/L had lower death risk. Although previous epidemiologic studies indicated an association between high serum HCO3(-) and increased mortality in MHD patients, this effect seems to be due substantially to the effect of MICS on survival.

Effect of Dietary Protein Intake on Serum Total CO2 Concentration in Chronic Kidney Disease

Metabolic acidosis is a feature of chronic kidney disease (CKD), but whether serum bicarbonate concentration is influenced by variations in dietary protein intake is unknown. For assessing the effect of diet, data that were collected in the Modification of Diet in Renal Disease study were used. In this study, patients with CKD were enrolled into a baseline period, then randomly assigned to follow either a low- or a usual-protein diet (study A, entry GFR 25 to 55 ml/min) or a low- or very low-protein diet, the latter supplemented with ketoanalogs of amino acids (study B, entry GFR 13 to 24 ml/min). Serum [total CO2] and estimated protein intake (EPI) were assessed at entry (n = 1676) and again at 1 yr after randomization, controlling for changes in GFR and other key covariates (n = 723). At entry, serum [total CO2] was inversely related to EPI (1.0 mEq/L lower mean serum [total CO2]/g per kg body wt increase in protein intake/d; P = 0.009). In an intention-to-treat analysis, the reduction in mean EPI in the low-protein group as compared with the usual-protein group (0.41 g/kg body wt per d) was independently associated with a 0.9-mEq/L increase in serum [total CO2], after adjustment for covariates (P < 0.001). No such effect was evident in study B, in which the very low-protein diet group received dietary supplements. Serum [total CO2] is inversely correlated with dietary protein intake in patients with CKD. A reduction in protein intake results in an increase in serum [total CO2].